Joint for concentric conductors



Oct. 13, 1942. 4.-, s'rRElB 2,298,516

JOINT FOR CONCENTRIC CONDUCTORS Filed Dec. 13, 1938 II UI Ill l a n a Q Q K) unumw mw uw v /w-M/ ATTORNEY Patented oi.13,1942 l i 2,298,515

.UNITED STTES PATENTl OFFICE 2,298,516 JOINT FOR CONCENTBJC CONDUCTORS Albrecht Streib, Port Jellerson Station, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application December 13, 1938, Serial No. 245,350 Claims. (Cl. 287-125) This invention relatesto anew and novel methcountered. By means of this invention, it will od of joining two lengths of concentric conducbe readily seen that it is not necessary to handle tors by means of an invisible joint to form one or rotate the conductors in order` to join them. continuous length of conductor of the same di- They may be placed in their iinal positions beameter throughout. 5 fore joining and once in position, may even be An object of this invention is to simplify and held by their insulation members if convenient improve the joints of concentric transmission without hindering the joining operation. lines generally. '.I'his invention will best he understood by re- Another object of this invention is to provide ferring to the accompanying drawing, in which: a simple and inexpensive joint which is mechanl0 Fig. 1 is a sectional view of a concentric conically strong and gives good electrical conductivductor;

ity to the line. Fig. 2 is a sectional view of an inner conductor Still another object c1 this invention is to prowith a slightly diierent binding member; vide a joint for a concentric conductor which per- Fig. 3 is a sectional view of an inner conducmits the change of the conductors without intor with a still further modiilcation in the bindteri'ering with the electrical characteristics 'of ing member; the line. Fig. 4 is an operative assembly view of one of In the construction of concentric transmission the inner concentric conductors and the adjustlines as used in short wave and television cirable binding member; cuits, it often becomes necessary to join several Fig. 5 is a detail o! a binding member which is lengths of conductors to form the center or inprovided with a central bore. ner conductor. When this is done by methods Referring now in detail to Fig. 1 of the drawknown in the prior art, such as soldering the ends ing, the outer conductor O is shown supporting over a plug, the whole length must be handled inner conductors A and B by means of any suitas a unit, which is ditilcult to manipulate. Fur- 2: able insulation material, such as a ceramic disc thermore, when alterations are to be made in the I. Conductor A has inserted in its lower end a line, the electrical characteristics of the circuit block or plug E which is provided with an inare consequently upset. Also, if screw threads ternal threaded wall, an aperture E1 and a reare used, such as tapped inserts and studs, to as- CESSed DCItiOn Ez- The COHdUCO!" B iS Provided semble the line, the whole length of the-conduc- With an end plus C, having internal threads C1. tor must be turned as a unit, which also presents In each case, the plugs C and E are soldered et installationdifficulties. As the inner conductor the ends oi the conductor and tapped with inof a transmission line must be of the same diamternal threads to receive the joining member or eter throughout its length, such methods as coubolt D. Also, in both conductors A and B, the plings and flanges known to the plumbing and opposite ends (not shown) are provided with alheating trades, cannot be used. temately arranged plugs. That is, if conductor The purpose of this invention is to provide an A is provided with plug E in its lower portion, improved transmission line employing novel the upper portion will then be provided with a means of readily joining the several lengths o1' plug C, In contradistinction thereto, conductor conductors into one continuous length of the B is provided with plug C in its upper portion and same diameter by means of invisible Joints. By the lower portion will be provided with a plug E. the use of this invention, the conductors may be Joining member D has a Woodm key K located broken up into several short lengths, which makes just above the lower threaded portion, the key it easier in handling and facilitates more rapid being arranged to have a 81mm g tit into a keyway installation. The joining Operation Of COlidllC- 40 extending through the total length of the inner tors of this invention is very simple and is not accomplished by means known in the prior art, bore of a spacing member S. To join conductors A and B o! Fig. 1, and to place them in their iinal such as applying a Stxllson wrench to the tubu lar conductors, but is accomplished by rotating posmons separated by spacer s' conductor A is a spacer which is inserted between the two adJafirst prepared for assembly by Sliding bolt D With cent conductor ends. rlhe spacer, itself, may be lock Washer L in Place (10Wn into Dip@ A until rotated by hand or by mean, of a strap wrench the large threaded head comes into contact with so no rough edges will be on che conthreaded E. Assuming right hand threads ductor to cause brushing to the inner surface of are Sed then bOlt D Will be advanced t0 position an outer conductor when high voltages are en- Shown in Fig. 4, by turning the bolt to the left,

when viewed looking upward at the lower end of bolt D.

The key K is now inserted and then spacer S slid over bolt D with the key K engaging keyway KS. Now, bolt D will turn when spacer- S is turned.

With conductor A prepared in this way, both conductors may be in their nal positions before joining.

By rotating spacer S to the left. viewed as before, bolt D will advance into block C because of the action of the threaded head in the threads of block E. Further turning to the left will then engage the lower threaded portion of bolt D with the threadsof block C in conductor B. Turning spacer S still more to the left advances binding member D until the threads on its head leave those of block E and it is pulled down against lock washer L and the shoulder portion directly above El of block E. Any further turning of member S then tightens the joint by means of threads in threads of members E and C naturally will have to be provided with threads of the same pitch, although not necessarilyof the same diameter. 'I'he inner conductor shown in Fig. 2 is generally similar to that of Fig. 1, except that the bolt D may be rotated by means of a'screw driver engaging in a slot SD, as well as by spacer S. Likewise, block E is slightly different in its construction, to provide for the shoulder portion for lock washer L. The binding operation of Fig. 2 is generally similar to that of Fig. 1, except that a screw driver must be used to advance the bolt D into spacer S. When the key of memberK D and the keyway KS are engaged, the operation is the same as that of Fig. 1, and while this arrangement is probably the simplest to construct, it of necessity requires that the conductor A must be of comparatively short length, or when conductor A can be prepared in advance so that member D is projecting, the method shown in Fig. 2 is then the best type to use. However, using this scheme with bolt D projecting, only one of the two conductors could be used in its nal position before joining. If pipe A is prepared with spacer S in place on bolt D, then both pipes may be in place before joining.

Fig. 3 shows a still further modication of this invention which is especially for use'in a television antenna, and in this case, spacer S is undercut :o allow the threaded portion of bolt D nearer the head to enter spacer S freely, the

operating of this modification being similar to' that oi Fig. l, that is, spacer S is turned by hand or by means of a strap wrench.

As shown by Fig. 5, this improved joint may be used for joining pipes for fluid transmission by providing a central aperture W. Also, in cases where it is not necessary, as in the case of a. transmission line, to maintain the same outside diameter, spacer S may be made hexagonal in shape, or provided with a small aperture in the side, for engaging a spanner wrench so that the Wrench might be used for tightening the joint. For instance, in joining two members together spaced a distance apart, where projecting bolt heads or nuts could not be used, this joint would serve the purpose very well.

Although only a few modifications of this invention are shown, it is to be distinctly understcod that the invention is not to be limited to the precise embodiments shown.

What is claimed is: 1. A transmission line comprising a conductor bolt D and block C. The' composed of a plurality of separate lengths, means for joining two lengths of the conductor together, said means including a recessed and a fshouldered portion at one end of each length, and a threaded portion at each of the ends thereof, aspacing member interposed between the two lengths of the conductor, a bolt having threads of the same hand and pitch as the threaded portion of said lengths, said bolt retained by the threaded portion of one of said lengths before they are joined together, said bolt located within said spacing member and having means whereby it is rotated with said spacing member tcjoin the two lengths of the conductor together by having its threads engage one of the lengths and to disengage the threads of another length by having its head extending in said recessed portionof one of said lengths until free and seating on the shouldered portion of one of said lengths, and its opposite end threaded into the other one of said lengths when they are completely joined together.

2. A transmission line comprising a conductor composed of a plurality of separate lengths, means for joining two lengths of the conductor together, said means including a recessed and a shouldered portion at one end of each length, and a threaded portion at each of the ends thereof, a spacing member interposed between the two lengths of the conductor, a threaded bolt having a threaded end portion and a slotted head, said bolt having threads of the same hand and pitch as the threaded portion of said lengths, said bolt retained by the threaded portion of one of said lengths before they are joined together, said bolt located within said spacing member and having means whereby it is rotated with said spacing member to join the two lengths of the conductor together by having its threads engage one of the lengths and to disengage the threads of another length by having its head extending in said recessed portion of one of said lengths until free and seating on the shouldered portion of one of said lengths, and its opposite end threaded into the other one of said lengths when they are completely joined together.

3. A transmission line-comprising Ia conductor composed of a plurality of separate lengths. means for joining two lengths of the conductor together, said means including a recessed and a shouldered portion at one end of each length, and a threaded portion at each of the ends thereof, a spacing member having a recessed portion, said spacing member interposed between the two lengths of the conductor, a threaded bolt having separate threads of the same hand and pitch as the threaded portion of said lengths, one of said separate threads being located beneath its head, the other separate thread being located at its end, said threaded bolt retained by the threads located beneath its head by the threaded portion of one of said lengths before they are joined together, said bolt located Within said spacing member and having means whereby it is rotated with said spacing member` to join the two lengths of the conductor together by having its threads engage one of the lengths and to disengage the threads of another length by having its head extending in said recessed portion of said spacing member until free and seating on the shouldered portion of one of sai lengths, and its opposite end threaded into th other one of said lengths when they are com pletely joined together,

4. A transmission line comprising a conducto Iand a threaded portion composed oi a plurality of separate lengths, means for joining two lengths of the conductor together, said means including a recessed and a shouldered portion at one end of each length,

at each of the ends thereof, a spacing member interposed between the two lengths or' the conductor, a bolt having threads of the same hand and pitch as the threaded portion of said lengths, said bolt retained by the threaded portion o1' one of said lengths before they are joined together, said bolt located within said spacing member and having means whereby it is rotated with said spacing member to Join the two lengths oi' the conductor together by having its threads engage one of the lengths and to disengage the threads of another length by having its head extending in said recessed portion of one of said lengths until free and seating on the shouldered portion 'oi' one of said lengths, and its opposite end threaded into the other one of said lengths when they are completely joined together, and a spring locking member interposed between the head of 5. A transmission line comprising a conductor composed of a. plurality of separate lengths, means for joining two lengths of the conductor together, said means including a recessed and a shouldered portion at one end of each length, and a threadd'portion at each of the ends thereof, a spacing member interposed between the two lengths of the conductor, a threaded bolt having a central aperture therein for passage of a fluid from one length of conductor to another. said bolt having threads of the same hand and pitch as thethreaded portion of said lengths, said bolt retained by the threaded portion of one of said lengths when they are joined together, said bolt located within said spacing member and having means whereby it is rotated with said spacing member to join the two lengths of the conductor together by having its threads engage one of the lengths and to disengage the threads of another length by having its head extending in said recessed portion of one of said lengths until free and seating on the shouldered portion of one of said lengths, and its opposite end threaded into the other one of said lengths when they are completely joined together.

ALBRECHT STREIB. 

